PLANTS. 1(39 



with, the fluids in the soil. This food consists of 

 vegetable and animal matters, or of whatever has 

 been such. Thirdly, it is important that a quantity 

 of moisture be always present in the soil, to dissolve 

 the focd of plants, or to serve as the medium for 

 conveying it first to the spongioles, and from thence 

 into and through the plant. Air, heat, and moisture 

 are all essential agents in preparing the food of 

 plants in the soil, and in giving vigour to vegetable 

 growth. 



It should be the object of the farmer and gardener 

 to aid these natural operations in cultivated crops j 

 and to repay the soil, by labour and skill, for the an- 

 nual tribute which they draw from it. These la- 

 bours consist in returning to it vegetable food (ma- 

 nure) equivalent to that which they annually take 

 from it ; in rendering it mellow and penetrable to the 

 roots of the growing crop ; in regulating the supply 

 of water, too much being as hurtful as too little ; and 

 in keeping the surface loose and porous, for the free 

 admission of air, heat, and moisture. Hence the ad- 

 vantage of deep tillage, perfect pulverization, drain- 

 ing, manuring, and the frequent use of the cultivator 

 among drilled or hoed crops ; and these considera- 

 tions also suggest one objection against using the 

 plough in the culture of these crops, and earthing or 

 hilling them to any considerable extent ; as both of 

 these modes of culture, ploughing and hilling, tend 

 to curtail the natural range of the roots, and, conse- 

 quently, to diminish the pasture and food of the crop. 



The depth and horizontal spread of roots are 

 greater than is generally apprehended, as they often 

 branch into minute filaments imperceptible to the 

 naked eye ; still these minute imperceptible fila- 

 ments collect" food for the parent plant. Jethro Tull, 

 the father of drill-husbandry, has given us a good 

 and satisfactory illustration of the great extension of 

 the roots of the common turnip, which we here in- 

 sert, not only to convince our readers of the fact, but 

 I. 



